This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Sepsis is a potentially life-threatening condition, in which immune system's reaction to an infection may injure body tissues far from the original infection. Neonatal sepsis is particularly dangerous in very low birth weight (VLBW) infants. Studies have shown that about 21% of VLBW infants who survied beyond 3 days have blood culture proven late-onset sepsis. Even if the infant survives, the adverse effect of sepsis can be long lasting, resulting in abnormal brain development. However, accurate early diagnosis in the neonates is difficult because there is no definitive diagnostic test;even blood cultures have an unacceptably low sensitivity. Therefore, the clinician must accept that a number of neonates will have treatment initiated for sepsis who do not have the disease. In order to treat rapidly all infants with sepsis and to minimize therapy for those without infection, improved technology is needed for detecting the onset of sepsis and studying its long-term effect on development. This pilot project will test and idetify MRI based methods for detecting brain injuries caused by stool infection using a newly developed mouse model. Aim 1: we will quantify changes in myelination caused by sepsis using high-resolution quantitative susceptibility imaging. Aim 2: we will quantify degradations in white-matter integrity and connectivity with high-resolution diffusion tensor imaging. The project will evaluate two promissing MRI methods for the early diagnosis of white matter injuries caused by neonatal sepsis. Successful early dedection of infection allows early intervention and prevents potential damages to neural development.